On some hardware designs the AUX+/- lanes are connected reversed to
SBU1/2 compared to the expected design by FSA4480.

Made more complicated, the otherwise compatible Orient-Chip OCP96011
expects the lanes to be connected reversed compared to FSA4480.

* FSA4480 block diagram shows AUX+ connected to SBU2 and AUX- to SBU1.
* OCP96011 block diagram shows AUX+ connected to SBU1 and AUX- to SBU2.

So if OCP96011 is used as drop-in for FSA4480 then the orientation
handling in the driver needs to be reversed to match the expectation of
the OCP96011 hardware.

Support parsing the data-lanes parameter in the endpoint node to swap
this in the driver.

The parse_data_lanes_mapping function is mostly taken from nb7vpq904m.c.

Reviewed-by: Neil Armstrong <neil.armstr...@linaro.org>
Signed-off-by: Luca Weiss <luca.we...@fairphone.com>
---
 drivers/usb/typec/mux/fsa4480.c | 71 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/drivers/usb/typec/mux/fsa4480.c b/drivers/usb/typec/mux/fsa4480.c
index e0ee1f621abb..cb7cdf90cb0a 100644
--- a/drivers/usb/typec/mux/fsa4480.c
+++ b/drivers/usb/typec/mux/fsa4480.c
@@ -60,6 +60,7 @@ struct fsa4480 {
        unsigned int svid;
 
        u8 cur_enable;
+       bool swap_sbu_lanes;
 };
 
 static const struct regmap_config fsa4480_regmap_config = {
@@ -76,6 +77,9 @@ static int fsa4480_set(struct fsa4480 *fsa)
        u8 enable = FSA4480_ENABLE_DEVICE;
        u8 sel = 0;
 
+       if (fsa->swap_sbu_lanes)
+               reverse = !reverse;
+
        /* USB Mode */
        if (fsa->mode < TYPEC_STATE_MODAL ||
            (!fsa->svid && (fsa->mode == TYPEC_MODE_USB2 ||
@@ -179,12 +183,75 @@ static int fsa4480_mux_set(struct typec_mux_dev *mux, 
struct typec_mux_state *st
        return ret;
 }
 
+enum {
+       NORMAL_LANE_MAPPING,
+       INVERT_LANE_MAPPING,
+};
+
+#define DATA_LANES_COUNT       2
+
+static const int supported_data_lane_mapping[][DATA_LANES_COUNT] = {
+       [NORMAL_LANE_MAPPING] = { 0, 1 },
+       [INVERT_LANE_MAPPING] = { 1, 0 },
+};
+
+static int fsa4480_parse_data_lanes_mapping(struct fsa4480 *fsa)
+{
+       struct fwnode_handle *ep;
+       u32 data_lanes[DATA_LANES_COUNT];
+       int ret, i, j;
+
+       ep = fwnode_graph_get_next_endpoint(dev_fwnode(&fsa->client->dev), 
NULL);
+       if (!ep)
+               return 0;
+
+       ret = fwnode_property_read_u32_array(ep, "data-lanes", data_lanes, 
DATA_LANES_COUNT);
+       if (ret == -EINVAL)
+               /* Property isn't here, consider default mapping */
+               goto out_done;
+       if (ret) {
+               dev_err(&fsa->client->dev, "invalid data-lanes property: %d\n", 
ret);
+               goto out_error;
+       }
+
+       for (i = 0; i < ARRAY_SIZE(supported_data_lane_mapping); i++) {
+               for (j = 0; j < DATA_LANES_COUNT; j++) {
+                       if (data_lanes[j] != supported_data_lane_mapping[i][j])
+                               break;
+               }
+
+               if (j == DATA_LANES_COUNT)
+                       break;
+       }
+
+       switch (i) {
+       case NORMAL_LANE_MAPPING:
+               break;
+       case INVERT_LANE_MAPPING:
+               fsa->swap_sbu_lanes = true;
+               break;
+       default:
+               dev_err(&fsa->client->dev, "invalid data-lanes mapping\n");
+               ret = -EINVAL;
+               goto out_error;
+       }
+
+out_done:
+       ret = 0;
+
+out_error:
+       fwnode_handle_put(ep);
+
+       return ret;
+}
+
 static int fsa4480_probe(struct i2c_client *client)
 {
        struct device *dev = &client->dev;
        struct typec_switch_desc sw_desc = { };
        struct typec_mux_desc mux_desc = { };
        struct fsa4480 *fsa;
+       int ret;
 
        fsa = devm_kzalloc(dev, sizeof(*fsa), GFP_KERNEL);
        if (!fsa)
@@ -193,6 +260,10 @@ static int fsa4480_probe(struct i2c_client *client)
        fsa->client = client;
        mutex_init(&fsa->lock);
 
+       ret = fsa4480_parse_data_lanes_mapping(fsa);
+       if (ret)
+               return ret;
+
        fsa->regmap = devm_regmap_init_i2c(client, &fsa4480_regmap_config);
        if (IS_ERR(fsa->regmap))
                return dev_err_probe(dev, PTR_ERR(fsa->regmap), "failed to 
initialize regmap\n");

-- 
2.42.0

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